89" 3-1/2" Bore Cylinder and Piston Kit For 1984-'99 Big Twins With Stock Cylinder heads and 4-5/8" Stroke Flywheels - Natural Aluminum FinishThis 3 1 2" bore cylinder and piston kit can be used to build an 89" stroker engine, or the replace the cylinders and piston in an engine with an existing 89" S&S stroker with stock cylinder heads. The kit contains S&S 3 1 2" bore cylinders, S&S 3 1 2" bore 4 5 8" stroker pistons,